Side impact and roll over inflatable head protector

ABSTRACT

A safety device for a motor vehicle which has a door frame and a door contained within the door frame. The safety device includes: a gas generator; a sensor for sensing at least one of a side impact and a roll-over for activating the gas generator; and an inflatable element connected to the gas generator for being inflated with gas from the gas generator upon activation of the gas generator. The inflatable element can thus assume a non-inflated mode and an inflated mode and can further be positioned adjacent the door in an inflated-mode thereof. The inflatable element is further made of fabric and includes: a first fabric layer defining a front part thereof; a second fabric layer defining a back part thereof, selected parts of the first fabric layer and second fabric layer being interconnected for defining one of linear and point shaped links where the first fabric layer and the second fabric layer are directly secured together. The inflatable element thus incorporates a plurality of substantially parallel elongated cells defined between the links, the cells being configured such that, upon inflation of the inflatable element with the gas from the gas generator, a lower edge portion of the inflatable element is tensioned. The inflatable element further includes an upper edge portion which is configured to be secured to the door frame all along a non-linear part of the door frame.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.09/127,918, filed Aug. 3, 1998, now U.S. Pat. No. 6,099,029, which is acontinuation of U.S. application Ser. No. 08/604,052, filed Feb. 20,1996, now U.S. Pat. No. 5,788,270.

FIELD OF THE INVENTION

This invention relates to a safety device, and more particulary relatesto a safety device in a motor vehicle such as a motor car.

BACKGROUND OF THE INVENTION

When a motor vehicle is involved in an accident there is a risk that thedriver and passengers within the vehicle will be injured. It has beenproposed to provide vehicles with safety devices to reduce the risk ofsuch injury.

Certain safety devices are intended to provide protection in the case ofa side impact. U.S. Pat. No. 5,322,322 discloses such a device. Aninflatable tube is initially stored in a recess in the door frame abovethe door of the vehicle, and the ends of the tube are pivotally anchoredto fixed points on the door frame. A sensor is provided to sense when anaccident occurs, and to initiate inflation of the tube. As the tubeinflates its length decreases, and it then extends linearly between thetwo fixed points on the door frame. The inflated tube provides someprotection for the head of a person sitting in the vehicle. However, thetube is inflated to a substantial pressure, and thus the head of aperson in the vehicle may tend to bounce off the tube. The tube may notcover the whole of the area of the window, and may not even cover thewhole of the upper part of the window. There is thus a risk that thehead of the person in the vehicle may move past the tube and passthrough the window opening. If a car is rolling over this is veryundesirable.

SUMMARY OF THE INVENTION

This invention seeks to provide an improved safety device.

According to this invention there is provided a safety device in a motorvehicle, the device comprising a gas generator, incorporating orassociated with a sensor adapted to sense a side impact or a roll-overand to activate the gas generator, and an inflatable element connectedto the gas generator to be inflated by gas from the gas generator, theinflatable element being made of fabric comprising a first layer todefine the front part of the inflatable element, and a second layer todefine the back part of the inflatable element, selected parts of thefirst layer and the second layer being inter-connected to define pointsor lines where the front part and back part of the inflatable elementare secured together, the inflatable element incorporating a pluralityof substantially parallel elongate cells, the inflatable element havingan edge portion secured to part of the door frame of the vehicle whichis non-linear, the inflatable element, when inflated, being positionedadjacent the door contained within the door frame.

The inflatable element, when inflated, is thus located between the headof a person sitting in the vehicle and an adjacent door. Usually such adoor is provided with a window and so the inflated element providesprotection from breaking glass from the window, and also prevents thehead of the person in the vehicle from striking the window, or frombeing thrown out through the window, as can happen, particularly withroll-over accidents.

Preferably the safety device is usually initially stored in a recessprovided in the doorframe.

Preferably the inflatable element is made of inter-woven fabric layers,the selected parts of the first layer and the second layer beinginter-woven. Preferably there is internal venting between the cells asthis may reduce undesirable bounce that might occur if the cells werediscrete and not vented to each other.

The cells may be immediately adjacent each other or may be spaced apart.At least some of the cells may be of conical form when inflated.

The inflatable element may be formed of a fabric with parts of thefabric being interwoven to form the cell or cells. The fabric may have asingle layer weight of less than 300 g/sq m, such as a weight of 175g/sq m

Preferably when the inflatable element is inflated the pressure of gasis approximately 3 bar. Preferably the inflatable element, wheninflated, extends past the B-post of the vehicle, to provide protectionfor the head of the driver. If the head of the driver should impact withthe B-post in an accident the consequences could be fatal.

In one embodiment the inflatable element incorporates a strap to connectpart of the inflatable element to the door frame. The strap is tight,that is, tensioned to a significant extent, when the inflatable elementis inflated.

Separate means may be provided to apply tension to part of theinflatable element then it is inflated, such as a piston and cylinder,adapted to be moved by gas from a gas generator when the inflatableelement is inflated, to apply tension to one edge of the inflatableelement, to hold the inflated element in a desired position.

In one embodiment the inflatable element is provided with means adaptedto move from an initial position to a further position on inflation ofthe inflatable element, an arrangement being provided to retain themeans in the further position. Thus a slider may be provided adapted toslide along a ratchet, and to be retained by the ratchet when it hasmoved to a further position.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood and so thatfurther features thereof may be appreciated the invention will now bedescribed by way of example with reference to the accompanying drawingsin which

FIG. 1 is a side view of the interior of a motor vehicle illustrating asafety device in accordance with the invention in an operative state,

FIG. 2 is a side view of part of the interior of a motor vehicleillustrating another safety device in accordance with the invention inthe operative state,

FIG. 3 is a sectional view of part of the embodiment of FIG. 2 in aplane perpendicular to a longitudinal axis of the vehicle,

FIG. 4 is a view of part of FIG. 2 showing an additional component ofthe safety device,

FIG. 5 is a side view of the interior of a motor vehicle provided withanother form of safety device in accordance with the invention, beforethe safety device moves to the operative state,

FIG. 6 illustrates the vehicle of FIG. 5 when the safety device is inthe operative state,

FIG. 7 is a sectional view of one form of safety device as shown in FIG.1 or in FIGS. 5 and 6 in a plane perpendicular to the verticaldirection,

FIG. 8 is a sectional view of another form of safety device as shown inFIG. 1 or in FIGS. 5 and 6, and

FIG. 9 is a view of part of an alternative inflatable element for use inthe embodiments of FIGS. 1, and 6.

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIG. 1 a safety device is illustrated which isintended to provide protection for a person 1 sitting in a seat 2 in thevehicle. In any accident in which the vehicle is decelerated the personwill tend to move forwardly towards the steering wheel 3, but will berestrained by a conventional seat belt or air-bag. In the case of a sideimpact or roll-over, there is a risk that the head of the person 1 willstrike the window in the door beside the person, or strike the B-post.There is also a risk that if, as most commonly happens, the glass in thewindow should break, the head of the person 1 may be thrown out of thewindow, especially in the case of roll-over.

The safety device shown in the operative state in FIG. 1 is initiallyretained in a recess provided in the door frame 4 located above the doorof the vehicle. The recess extends over more than simply a linearportion of the door frame so that the two ends of the recess are not inalignment with the main part of the recess.

The safety device comprises a gas generator 5, which is adapted togenerate gas, such as cold gas. The gas generator incorporates, or isassociated with, a sensor which senses a side impact and/or a roll-oversituation to activate the gas generator at an appropriate instant. Thegas generator is connected by a hose 6 to a duct 7. The duct 7 formspart of an inflatable element. The inflatable element incorporates aplurality of parallel substantially vertical, substantially cylindricalcells 8. The inflatable element may be made of interwoven fabric. Such afabric comprises a first layer that defines the front of the inflatableelement—that is to say the part that is visible in FIG. 1—and a secondlayer that defines the back part—that is to say the part that isadjacent the window in FIG. 1—selected parts of the first region and thesecond region being interwoven to define links in the form of points orlines where the front part and the back part of the inflatable elementare secured together. A technique for making an inflatable element ofinter-woven fabric is described in more detail in International PatentPublication WO90/09295.

A webbing strap 9 that forms part of the inflatable element extends fromthe end of the inflatable element near the duct 7 which is connected tothe hose 6 to an anchoring point 10 on the door frame 4. The edge of theduct 7 between the points 11, adjacent the top of the B-post 12, and 13,at the lower part of the A-post, in the region of the dashboard 14, isfixed securely to the door frame 4. Consequently, it is to be understoodthat the upper edge of the inflatable element has a non-linearconfiguration which conforms with the non-linear configuration of theupper part of the door frame 4 by virtue of the inflatable element beingsecured, at an upper edge portion thereof, to the door frame all alone anon-linear part of the door frame as shown in the figures. A substantialpart, in fact virtually all, of the upper edge of the inflatable elementis secured to the upper part of the door frame.

When an accident such as side impact occurs the gas generator generatescold gas which passes through the hose 6 to the duct 7, and theninflates the cells 8. The inflatable element thus moves from its initialstored position within the recess in the door frame to the operativeposition shown in FIG. 1. The inflatable element then extends downwardlyfrom the top of the door frame to form a flat structure located betweenthe head of the person 1 and the adjacent window. As the cylindricalcells inflate the length of the lower edge 15 or the inflatable elementis reduced, and thus the lower edge, together with the webbing strap 9extend substantially tightly from the point 10 to the point 13. It is tobe noted that the part of the door frame 4 between the points 10 and 13is not linear, and defines, with the linear lower edge of the inflatedelement, a triangular area which is covered by the inflated element.

The lower edge of the inflated element decreases by about 10% betweenthe uninflated state and the inflated state. The inflated element isfully inflated within about 15 ms. The total thickness of the inflatedelement, when inflated is approximately 30-40 mm. The seams ofinterweaving of the front part and the back part of the inflated elementare approximately 30-40 mm apart, so that the resultant cells arecylindrical when inflated. The total volume of gas within the inflatedelement may be between 7 and 9 litres, and the gas may be at a pressureof about 3 bar. While the inflated element is not provided with a ventto vent gas from within the element to the atmosphere, so that theinflated element, when inflated, remains inflated for a long period oftime—to provide protection in the case of a protracted roll-over—thereis venting between at least selected adjacent cells 8, to avoid anysevere rebound. Thus if the head of the person in the vehicle impactswith the inflated element the pressure of gas within the whole element,or at least a substantial part of the element will rise, thus giving a“soft” impact. If each cell were sealed with no venting of this type,there would be a risk of severe rebound.

The weight of the fabric should be kept to be as low as possible, sothat if the inflatable element should impact with the head of the personin the vehicle as the inflatable element is inflated no harm will bedone. It is thought that a material hating a weight of less that 300g/sq m, such as 175 g/sq m may be used.

It is to be noted that part of the inflated element extends rearwardlybeyond the point 11, and is thus located between the head of the person1 and the top of the B-post. Thus the risk of the head of the personimpacting with the B-post is minimized. Since the upper edge of theinflatable element is secured to the upper part of the door frame alongsubstantially the whole of its length, there is virtually no risk thatthe head of the occupant will pass between the upper edge of theinflatable element and the upper part of the door frame, with the headof the occupant of the vehicle thus inadvertently emerging from the bodyshell of the vehicle.

FIGS. 2 to 4 illustrate a second embodiment of the invention. In thisembodiment an inflatable element 20 is provided which is initiallystored in a recess provided in the door frame 21 of a motor vehicle. Agas generator 22 is provided, which again incorporates or is associatedwith a sensor or detector which activates the gas generator at anappropriate time. The gas generator is connected by a duct 23 to aninflatable part 24 of the inflatable element 20. The gas generator 22 islocated in the door frame 21 of the vehicle, but alternatively could bepositioned in the B-post.

The inflatable part 24 or the inflatable section of the inflatableelement 20 is formed from two layers of fabric, as in the embodiment ofFIG. 1, with the front layer and the back layer of the fabric beingwoven together at selected points 25. The selected points 25 arearranged in vertically extending columns and serve to divide theinflatable part 24 into a plurality of vertical parallel chambers. Thespaces between the selected points 25 permit internal venting betweenadjacent chambers.

The inflatable part 24 of the inflatable element 20 is adapted to belocated adjacent the head of an occupant of the motor vehicle, and,towards the rear of the inflatable element, when in the positionillustrated in FIG. 2, the inflatable part of the inflatable elementextends from the top to the bottom of the inflatable element in a rearregion and subsequently, the upper edge of the inflatable part extendsdownwardly towards the lower edge of the inflatable element, in a sensedirected towards the A-Post 26. The remaining part or non-inflatablesection of the inflatable element comprises a web or sheet 27 whichextends from the inflatable part 24 to the part of the door frame 21above the door and to the A-post. The web or sheet 27 is thus secured toparts of the door frame that are non-linear. It is to be appreciated,therefore, that in this embodiment of the invention the upper edge ofthe inflatable element is of non-linear form and is of the sameconfiguration as the non-linear part of the door frame which extendsforwardly from the B-post and which incorporates the A-post. The upperedge of the inflatable element, or at least a substantial part of thatupper edge, is securely fixed to the upper part of the door frame, thusagain minimizing any risk of the head of the occupant emerging from thebody shell between the upper edge of the inflatable element and theupper part of the door frame.

Referring to FIG. 3 the edge of the sheet 27 that is secured to the doorframe 21 may terminate with a bead 28 that is received within a slot 29formed in the door frame, the mouth of the slot being narrower than thebase so that the bead 28 can slide axially within the slot, but cannotescape from the slot. A cable 30 is connected to the end of the bead, ascan be seen in FIG. 4, the cable being connected to a tensioning device31. The tensioning device may comprise a piston in a cylinder associatedwith a gas generator to generate gas which moves the piston within thecylinder to apply tension to the cable 30 and thus to the bead 28. Aratchet or the like may hold the piston in place when it has been movedby the gas. The gas generator that supplies gas to the piston may be thegas generator 22 or may be a separate gas generator that is triggeredsimultaneously with the main gas generator.

When an accident occurs the inflatable element 20 moves from its storedposition to the operative position shown in FIG. 2, and tension isapplied to the inflatable element 20 by the distention of the inflatablepart 24, and by the tension applied to the bead 28. The inflated element20 is thus held firmly in position to provide protection for the head ofthe person sitting in the motor vehicle. The thickness of the element 20and the weight of the material used should be as described withreference to the embodiment of FIG. 1.

FIGS. 5 and 6 illustrate another embodiment of the invention intended toprovide protection not only for a person in the front seat of a motorvehicle such as a motor car, but also for a person in the rear seat ofthe vehicle.

Referring to FIG. 5, a recess 40 is provided in the doorframe 41 of amotor vehicle, the recess extending over both the front door 42 and therear door 43. The recess extends from a point 44 located near the lowerend of the A-post to a point 45 located near the lower end of theC-post.

A channel 46 is provided on the B-post, extending vertically. In thechannel 46 is a ratchet R, and received within the upper end of thechannel 46 is a ratchet engaging slide member 47. The slide member 47 isconnected to a tab 48 which forms part of an inflatable element 49 (seeFIG. 6), which is initially stored within the recess 40.

The inflatable element 49 is shown in the inflated state in FIG. 6. Theinflatable element has its top edge 50 secured to the part of the doorframe 41 that extends above the doors 42, 43 of the motor vehicle. Thetop edge of the inflatable element is of non-linear configuration, andhas a configuration which corresponds with the non-linear configurationof the upper part of the door frame. The design of the inflatableelement is similar to that shown in FIG. 1, with the inflatable elementpresenting a plurality of parallel cells, which when inflated aresubstantially cylindrical. The structure of the inflatable element 49may be the same as that described with reference to FIG. 1.

A gas generator 51 is provided which is connected to the inflatableelement in such a way that when the gas generator is activated by asensor that is formed integrally with the gas generator, or which isassociated with the gas generator, and which responds to a side impactor to a roll-over situation to activate the gas generator, gas isinitially supplied to the cells 52, 53, which are aligned with the tab48. Thus initially, as the inflatable element 49 inflates, the cells 52and 53 inflate and move the ratchet engaging slide member 47 downwardly.The ratchet engaging slide member thus moves down the slot 46 to theposition shown in FIG. 6. The ratchet engaging slide member 47 engagesthe ratchet, and thus holds the tab 48 in its lower position.

The rest of the cells 54 of the inflatable element are then inflated,and the inflatable element then extends fully across the upper parts ofthe windows in the doors 42, 43 of the motor vehicle. It can be seenthat the lower edge of the inflated element 49 extends between thepoints 44 and 45 at the ends of the recess 40. As the inflatable element49 inflates, so the length of the lower edge thereof decreases as aconsequence of the inflation of the cells of the inflatable element.This reduction in the length of the lower edge, together with the actionof the ratchet engaging slide member 47 ensures that the inflatedelement is retained in position as illustrated after it has beeninflated.

FIG. 7 is a cross section showing the nature of the cells of theinflated element of FIG. 1 and of FIGS. 5 and 6. It can be seen that thecells are immediately adjacent to each other and are only separated bynarrow regions where the fabric forming the front part of the inflatedelement has been woven with the fabric forming the back part of theinflated element. However, FIG. 8 illustrates an alternativepossibility, in which the regions of fabric between the cells that arewoven together are relatively wide, the cells thus being separated bywebs of fabric. The advantage of this latter possibility is that asmaller volume of gas may be required to fully inflate the inflatableelement, meaning that the inflatable element may be inflated morerapidly.

FIG. 9 illustrates an alternative form of inflatable element comprisinga plurality of cells 60 or inflatable sections. The upper edge of theinflatable element is of non-linear form and is connected to thenon-linear portion of the door frame above the door. The configurationof the upper edge of the inflatable element and the configuration of thedoor frame correspond. It can be seen that each cell 60 is ofsubstantially conical form, the cells being arranged adjacent each otherand being parallel with each other. Between the cells are invertedtriangular portions 61 or non-inflatable sections where the fabricforming the cells is interwoven.

When cells of this type are inflated, the length of the lower edge ofthe arrangement contracts, whereas the length of the upper edge of thearrangement remains constant.

An arrangement of this type can be used, therefore, to ensure that thelower edge of the element, when inflated, is under some tension.

Whilst in the arrangement illustrated in FIG. 9, the cells areimmediately adjacent each other, it is to be appreciated that a similareffect may be achieved if the cells are spaced apart. It is possible toreplace at least part of the inverted triangular region 61 with furtherconical cells of an inverted orientation.

Whilst in the described embodiments of the invention, the inflatableelement has been described as being made utilising a technique in whichtwo layers of fabric are interwoven to define points or lines where thefront layer and the rear layer are interwoven, it would be possible toform embodiments of the invention utilising two discrete layers offabric which are interconnected by stitching.

What is claimed is:
 1. A safety device in a motor vehicle having a doorframe comprising: a gas generator; a sensor associated with said gasgenerator for sensing one of a side impact and a roll-over thatactivates said gas generator; an inflatable element connected to saidgas generator to be inflated by gas from said gas generator uponactivation of said gas generator, said inflatable element comprising: afirst layer to define a front part of said inflatable element; a secondlayer to define a back part of said inflatable element, with selectedparts of the first layer and the second layer being interconnected todefine regions where the front part and the back part of said inflatableelement are secured together forming elongated cells; and an upper edgeportion secured at selected points to a non-linear part of the doorframe, said upper edge portion being non-linear and conforming to thenon-linear part of the door frame whereby, when inflated, saidinflatable element is positioned adjacent a window of a door containedin the door frame and said cells being designed such that on inflationof the inflatable element, a line of tension is created along saidinflatable element; and a strap connected to a part of the inflatableelement and to the door frame.
 2. A safety device according to claim 1,wherein the inflatable element, in a non-inflated mode, is initiallystored in a recess provided in the door frame.
 3. A safety deviceaccording to claim 1, wherein said inflatable element is made of fabricand said first and second layers are first and second fabric layers. 4.A safety device according to claim 3, wherein the first fabric layer andthe second fabric layer are interconnected at the selected parts thereofby being interwoven with on another at said regions.
 5. A safety deviceaccording to claim 1, wherein the cells are configured to be in gas flowcommunication with one another.
 6. A safety device according to claim 1,wherein the cells are spaced apart from each other.
 7. A safety deviceaccording to claim 1, wherein at least some of the cells have a conicalshape when the inflatable element is inflated.
 8. A safety deviceaccording to claim 1, wherein the inflatable element, when inflated,extends past a B-post of the vehicle.
 9. A safety device in a motorvehicle having a door frame comprising: a gas generator; a sensorassociated with said gas generator for sensing one of a side impact anda roll-over that activates said gas generator; an inflatable elementconnected to said gas generator to be inflated by gas from said gasgenerator upon activation of said gas generator, said inflatable elementcomprising: a first layer to define a front part of said inflatableelement; a second layer to define a back part of said inflatableelement, with selected parts of the first layer and the second layerbeing interconnected to define regions where the front part and the backpart of said inflatable element are secured together forming elongatedcells; and an upper edge portion secured at selected points to anon-linear part of the door frame, said upper edge portion beingnon-linear and conforming to the non-linear part of the door framewhereby, when inflated, said inflatable element is positioned adjacent awindow of a door contained in the door frame and said cells beingdesigned such that on inflation of the inflatable element, a line oftension is created along said inflatable element; and a tensioningdevice for applying tension to the inflatable element when it isinflated.
 10. A safety device according to claim 9, wherein theinflatable element, in a non-inflated mode, is initially stored in arecess provided in the door frame.
 11. A safety device according toclaim 9, wherein said inflatable element is made of fabric and saidfirst and second layers are first and second fabric layers.
 12. A safetydevice according to claim 11, wherein the first fabric layer and thesecond fabric layer are interconnected at the selected parts thereof bybeing interwoven with one another at said regions.
 13. A safety deviceaccording to claim 9, wherein the cells are configured to be in gas flowcommunication with one another.
 14. A safety device according to claim9, wherein the cells are spaced apart from each other.
 15. A safetydevice according to claim 9, wherein at least some of the cells have aconical shape when the inflatable element is inflated.
 16. A safetydevice according to claim 9, wherein the inflatable element, wheninflated, extends past a B-post of the vehicle.
 17. A safety device in amotor vehicle having a door frame comprising: a gas generator; a sensorassociated with said gas generator for sensing one of a side impact anda roll-over that activates said gas generator; an inflatable elementconnected to said gas generator to be inflated by gas from said gasgenerator upon activation of said gas generator, said inflatable elementcomprising: a first layer to define a front part of said inflatableelement; a second layer to define a back part of said inflatableelement, with selected parts of the first layer and the second layerbeing interconnected to define regions where the front part and the backpart of said inflatable element are secured together forming elongatedcells; and an upper edge portion secured at selected points to anon-linear part of the door frame, said upper edge portion beingnon-linear and conforming to the non-linear part of the door framewhereby, when inflated, said inflatable element is positioned adjacent awindow of a door contained in the door frame and said cells beingdesigned such that on inflation of the inflatable element, a line oftension is created along said inflatable element; and position retainingmeans connected to a part of the inflatable element for retaining aposition of the part of the inflatable element on the door frame whenthe inflatable element is inflated, the position retaining meanscomprising: a component adapted to move from an initial position to afurther position upon inflation of the inflatable element; and meansoperatively connected to the component for retaining the component insaid further position.
 18. A safety device according to claim 17,wherein the inflatable element, in a non-inflated mode, is initiallystored in a recess provided in the door frame.
 19. A safety deviceaccording to claim 17, wherein said inflatable element is made of fabricand said first and second layers are first and second fabric layers. 20.A safety device according to claim 19, wherein the first fabric layerand the second fabric layer are interconnected at the selected partsthereof by being interwoven with one another at said regions.
 21. Asafety device according to claim 17, wherein the cells are configured tobe in gas flow communication with one another.
 22. A safety deviceaccording to claim 17, wherein the cells are spaced apart from eachother.
 23. A safety device according to claim 17, wherein at least someof the cells have a conical shape when the inflatable element isinflated.
 24. A safety device according to claim 17, wherein theinflatable element, when inflated, extends past a B-post of the vehicle.